A river dies from the mouth up... Think about that

With the Murray River, only opinions flow freely

• Peter Ker
• April 4, 2009

Going, going ... Lake Bonney in South Australia is slowly evaporating after being disconnected from the Murray RIver. Photo: Angela Wylie

FORGET what the poets and the bush balladeers tell you; the Murray River does not flow neatly like a ribbon through the Australian landscape.

Imagine instead a paintbrush flicked across a canvas, leaving a thick, central line with hundreds of dots above and below. This is how the Murray looks from above; a central canal bled by hundreds of appendixes. Lakes, wetlands, billabongs and false starts, each taking their own ration from the river's dwindling flows.

As the buyback of farmers' water entitlements gathers pace in south-eastern Australia, a second rationalisation of the Murray Darling Basin is also under way.

Natural river appendixes — either wasteful drains or environmental assets, depending on your point of view — are being pruned from the main Murray channel in a bid to maximise flows down the river.

As Victoria moves slowly towards decommissioning the man-made Lake Mokoan in the state's north, residents in the South Australian town of Barmera have already had a taste of the future. This arid, landlocked region was made habitable when an an offshoot of the Murray pooled to create the 1700-hectare Lake Bonney.

The fresh water and clean beaches made the lake a recreational treasure, attracting visitors from afar and providing the perfect backdrop to Barmera's picturesque main street.

But as the drought has worsened over the past 18 months, the decision was made to disconnect Lake Bonney from the Murray. An earthen wall, littered with the skeletons of dead fish, now keeps river water from flowing into the lake. Water quality has eroded as the lake level has declined; annual evaporation off the lake is 10 per cent of total water use for irrigation in the Riverland district.

Gavin McMahon is in charge of the local irrigation trust, but even he acknowledges that life in Barmera is better with a full lake. "Without the lake, the town would really struggle," he says.

But it's far from the only casualty. The South Australian Government has disconnected 27 wetlands from the Murray and more will follow soon.

Victoria has fewer natural wetlands that feed from the Murray, so is less affected, but experts such as Mike Young says difficult decisions could lie ahead for sites such as the Barmah Forest. Professor Young recently argued in Melbourne for further downsizing of the Murray system, saying "we can't keep it all".

Peter Hill grows fruit about 20 minutes' drive from Lake Bonney, and knows a bit about pruning for efficiency. Able to take just 18 per cent of his water entitlement out of the Murray this year, Mr Hill hacked back his orange trees, removing the least productive branches to minimise water consumption. He doesn't understand why he can only take 18 per cent of his water while Victorian farmers can take more than 30 per cent and some in NSW can take more than 90 per cent.

Victoria is clinging to a water trading limit that prevents more than 4 per cent of water entitlements being traded out of local districts. The policy, designed to protect Victorian towns, limits the amount of water that can be purchased to flush down the ailing river and forces buyback schemes to target other states.

"If we keep on putting in hurdles to slow down the reform, it's not going to be good for the future," Mr Hill says.

A bill before South Australia's Parliament threatens to ban such trading limits and the locals desperately want Victoria to follow suit.

Mr McMahon says South Australians aren't looking for favouritism. "We just want a level playing field. The reasons Victorians use is that (removing the limit) will hurt their agriculture. Well doesn't that apply to South Australia? It has got to be the same everywhere, otherwise somebody will be plucked off."